镍含量对高碳铁素体不锈钢铸态组织及腐蚀性能的影响

Effect of Nickel Content on As-Cast Microstructure and CorrosionResistance of High Carbon Ferritic Stainless Steel

采用光学显微镜、扫描电镜、显微硬度计、Thermal-calc热力学软件等设备和腐蚀试验,研究了镍含量对高碳铁素体不锈钢Cr30A铸态组织及耐腐蚀性能的影响。铸态组织分析结果表明,当镍含量低于1.5%时,可以得到铁素体+离异共晶铬系碳化物组织;镍含量高于2.0%时,可以得到铁素体+铁素体/铬系碳化物共析团的组织类型。耐腐蚀试验表明,由于相界面及贫铬区减少,含铁素体+离异共晶铬系碳化物合金的耐腐蚀性能显著优于含铁素体+铁素体/铬系碳化物共析团的合金。

Using OM,SEM,hardness tester,Thermal-calc thermodynamics software,and corrosion test method,the influence of nickel content on the as-cast microstructure and corrosion resistance of high-carbon ferritic stainless steel Cr30A was studied.The as-cast microstructure analysis results show that when the nickel content is less than 1.5%,the ferrite+divorced eutectic chromium carbide microstructure can be obtained;when the nickel content is more than 2.0%,the microstructure with ferrite+ferrite/Cr carbide eutectoid group can be obtained.Corrosion resistance experiments show that the corrosion resistance of the Ni-containing Cr30A alloy with ferrite+divorced eutectic chromium carbide structure is significantly better than that of the Ni-containing Cr30A alloy with ferrite+ferrite/Cr carbide eutectoid group due to the reduction of phase interface and chromium-depleted zone.